I have a1995 Saturn sl1 That keeps over heating and for some reason my fan doesn't kick on either idling or driving. I have also taken the tstat out to see if out would still overheat which it does. Could my fan not coming on cause it to overheat? Do i need a tstat in for my fan to turn on?
yes, the fan not coming on can cause it to overhet and the most likely cause of the fan not working is the temp. sensor for the fan. the fan could have gone bad but you would need to check for current at the fan with the engine at temperature. no current, probably the sensor, current, probably the fan motor. there are always other things that could be wrong but these two are the best to check first.
Where is the sensor located and how test for current at both places?
the sensor is usually located in the cyl head near the thermostat housing.. to test for current at the fan with the engine at temperature, you will need to unplug the fan and probe the connector with a test light.
I forgot to mention that it only overheats when i drive it. Sitting and idling it doesn't over heat. Beings my tstat is at the bottom this should be where the sensor is correct?
this system is a bit complicated due to its control system being tied to the ac and possibly the power control module or engine control module (computer). it should have a 1 wire sensor and a 2 wire sensor. the 1 wire should control the gauge and the 2 wire should control the fan. both should be screwed into the engine on the cylinder head or block. this model seems to also have a fan control unit mounted near the fan motor. sorry i can't be more help. the cheapest fix is to wire the fan motor to come on whenever the key is on. another is to wire it to a switch that you turn on and off manually. they also sell a kit to use a different temp. sensor than the factory that is adjustable so you can set the fan to turn on and off at a setting (temperature) set by you.sorry i can't be more help.